Expression of a cloned rat brain potassium channel in Xenopus oocytes   总被引：21，自引：0，他引：21  

M J Christie  J P Adelman  J Douglass  R A North 《Science (New York, N.Y.)》1989,244(4901):221-224

Potassium channels are ubiquitous membrane proteins with essential roles in nervous tissue, but little is known about the relation between their function and their molecular structure. A complementary DNA library was made from rat hippocampus, and a complementary DNA clone (RBK-1) was isolated. The predicted sequence of the 495-amino acid protein is homologous to potassium channel proteins encoded by the Shaker locus of Drosophila and differs by only three amino acids from the expected product of a mouse clone MBK-1. Messenger RNA transcribed from RBK-1 in vitro directed the expression of potassium channels when it was injected into Xenopus oocytes. The potassium current through the expressed channels resembles both the transient (or A) and the delayed rectifier currents reported in mammalian neurons and is sensitive to both 4-aminopyridine and tetraethylammonium.  相似文献   

Regulating marine transplantation     

North WJ 《Science (New York, N.Y.)》1973,179(4079):1181

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In vivo characterisation of two Australian isolates of Marek's disease virus including pathology,viral load and neuropathotyping based on clinical signs          下载免费PDF全文

SJ Wajid  SW Walkden‐Brown  BA Vanselow  AFMF Islam  KG Renz 《Australian veterinary journal》2015,93(7):240-247

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奥地利黑松引种造林试验初步分析          下载免费PDF全文

刘永红  樊军锋  杨培华 《西北农林科技大学学报(自然科学版)》2005,33(10):33-36

在陕西周至、永寿、黄陵及延安进行了奥地利黑松引种造林试验。初步结果表明,奥地利黑松对引种地气候表现出较强的适应性,造林平均成活率达到73.7%;树高生长量与海拔、≥10℃积温和年降雨量密切相关;选用2年生容器苗在阳坡造林可提高林木生长量;4年生奥地利黑松最大平均树高和最大平均地径生长量分别超过当地对照油松15.16%和8.4%。初步认为,奥地利黑松适于在陕西秦岭以北、延安以南生长,特别在黄土高原区表现良好,值得推广。  相似文献   

Contribution of stream channel erosion to sediment yield from an urbanizing watershed   总被引：2，自引：0，他引：2  

SW Trimble 《Science (New York, N.Y.)》1997,278(5342):1442-1444

Stream channel erosion has long been suspected as the major contributor to long-term sediment yield from urbanizing watersheds. For San Diego Creek in southern California, measurements from 1983 to 1993 showed that stream channel erosion furnished 10(5) megagrams per year of sediment, or about two-thirds of the total sediment yield. Thus, because channel erosion can be a major source of sediment yield from urbanizing areas, channel stabilization should be a priority in managing sediment yield.  相似文献   

The decision to seed hurricanes     

Howard RA  Matheson JE  North DW 《Science (New York, N.Y.)》1972,176(4040):1191-1202

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The effect of conditions of storage on the respiration of apples. VI. The effects of temperature and controlled atmosphere storage on the relationship between rates of production of ethylene and carbon dioxide     

J.C. Fidler  C. J. North 《The Journal of Horticultural Science and Biotechnology》2013,88(2):237-243

Studies on freshly harvested fruit of three apple cultivars kept in air or under C.A. conditions at 12°, 7.2°, 3.3° and 0 °C have shown that the initiation of ethylene production is not necessarily associated with the onset of the respiration climacteric, and therefore cast doubt on the belief that ethylene is a ripening hormone. The dissociation of the two phenomena was effected by low temperatures and by storage under C.A. conditions.

The studies showed also that there is a linear relationship between rate of production of ethylene and its concentration in the intercellular spaces of the fruit.  相似文献   

The Effect of Conditions of Storage on the Respiration of Apples: III. The Effect of Modulation of Temperature on the Respiration of Cox’s Orange Pippin Apples,and on the Extent of Low Temperature Injury     

J. C. Fddler  C. J. North 《The Journal of Horticultural Science and Biotechnology》2013,88(4):421-428

When apples which develop low temperature breakdown (LTB) at 32° F. are moved from 32° F. to 65° F. for 3 to 5 days at about the 7th to 8th week of storage, they subsequently develop within a given period of storage less LTB than apples kept at 32° F. continuously.

The respiration of apples susceptible to LTB increases steadily during storage at 32° F. If these apples are warmed to 65° F. during the period of exposure to 32° F., the subsequent rate of respiration at 32° F. is lower than before warming, and continues at a lower rate than for apples kept at 32° F. continuously.

If the apples are moved to 38° F., without an intermediate treatment at 65° F., the rate of respiration is higher than for apples at 38° F. continuously, and this higher rate persists.

If there is an intermediate wanning period at 65° F., the respiration of apples moved from 32° to 38° F. is of the same order as that for apples kept at 38° F. continuously.

The respiratory quotient of apples at 32° F. or at 38° F., which is indicative of the type of respiratory activity, is typical for the temperature at which it is measured, and is not affected by the warming treatment. The effects of wanning on both the incidence of LTB and respiration are similar for apples stored in air and in 2% oxygen: 98% nitrogen.  相似文献   

Africa’s wooden elephant: the baobab tree (Adansonia digitata L.) in Sudan and Kenya: a review     

Jens Gebauer  Yahia O. Adam  Aida Cuní Sanchez  Dietrich Darr  Muneer E. S. Eltahir  Kamal E. M. Fadl  Gabriele Fernsebner  Michael Frei  Tsige-Yohannes Habte  Karl Hammer  Mauricio Hunsche  Henry Johnson  Maha Kordofani  Michael Krawinkel  Florian Kugler  Eike Luedeling  Tarig E. Mahmoud  Anthony Maina  Dagmar Mithöfer  Chimuleke R. Y. Munthali  Georg Noga  Rabea North  Willis O. Owino  Kathleen Prinz  Freda K. Rimberia  Amina Saied  Martin Schüring  Anne Sennhenn  Martin A. Späth  Mohamed E. N. Taha  Andreas Triebel  Florian Wichern  Martin Wiehle  Nicole Wrage-Mönnig  Katja Kehlenbeck 《Genetic Resources and Crop Evolution》2016,63(3):377-399

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Canopy microclimate response to pattern and density of thinning in a Sierra Nevada forest     

T.R. Rambo  M.P. North 《Forest Ecology and Management》2009

Restoring Sierra Nevada mixed-conifer forests after a century of fire suppression has become an important management priority as fuel reduction thinning has been mandated by the Healthy Forests Restoration Act. However, in mechanically thinned stands there is little information on the effects of different patterns and densities of live-tree retention on forest canopy microclimate. This study compared gradients of air temperature and vapor pressure deficit (VPD) through the vertical forest profile among an overstory-thin, an understory-thin, an un-thinned control, and a riparian environment in a Sierra Nevada mixed-conifer forest. Temperature and humidity were recorded for a year by 60 data loggers arrayed in 12 trees at 5, 15, 25, 35, and 45 m above the forest floor. Both thinning treatments had significantly more extreme summer daily ranges of temperature and VPD than the control across heights. The overstory-thin resulted in the greatest maximum temperatures, VPDs, and VPD range among all sensors at 5 m, and significantly higher summer maximum temperatures and VPDs than the control in lower strata (≤15 m). The understory-thin also had significantly higher summer maximum temperatures than the control (≤15 m), but these too were significantly less than in the overstory-thin nearest the surface at 5 m. Understory thinning did not alter the mean or range of microclimate as much as overstory thinning. Riparian microclimate had significantly lower minimums and means, and greater daily ranges of temperatures and VPDs than the control. Results suggest that thinning canopy cover significantly increases the extremes and variability of understory microclimate compared to thinning from below and no-thin treatments.  相似文献